On Thu, 20 Apr 2006, Shawn Pearce wrote: > Based on Linus' comment I changed your patch to just the following. > It still produced the 46M pack file, so the first hunk apears to > not have had much of an affect with this data. > > From a running time perspective it appears as though this patch is > making things slightly better, not worse. I ran it a few times > for each case always using the 46M pack as input for > "git-repack -a -d -f". > > 'next' 137.13 real 95.82 user 25.24 sys > 'next'+patch 131.62 real 89.35 user 28.56 sys > > but even if the running time was an extra 6 seconds I'd still rather > spend 4% more running time to use 1/2 the storage space. > > > diff --git a/pack-objects.c b/pack-objects.c > index 09f4f2c..f7d6217 100644 > --- a/pack-objects.c > +++ b/pack-objects.c > @@ -1052,7 +1052,7 @@ static int try_delta(struct unpacked *cu > if (cur_entry->delta) > max_size = cur_entry->delta_size-1; > if (sizediff >= max_size) > - return -1; > + return 0; > delta_buf = diff_delta(old->data, oldsize, > cur->data, size, &delta_size, max_size); > if (!delta_buf) I can confirm this is indeed the best fix so far. Any "smarter" solution I could think of did increase the size of the final pack quite spectacularly and rather unexpectedly with Shawn's repository. Of course removing the if (sizediff >= max_size) entirely does produce a smaller pack (39MB) but it takes about twice the CPU. With the patch above the Linux kernel pack is 0.3% smaller with 1% more CPU usage. But like for the diff-delta hash list limiting code this small overhead is certainly a good compromize to avoid big degradations in some other cases. Nicolas - : send the line "unsubscribe git" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html